To increase the integration density of semiconductor devices, lithography techniques using extreme ultraviolet (EUV) light in a wavelength range of about 13.5 nm are now being developed. In lithography in such an EUV wavelength range, reflection-type lithography masks are used which have a reflection layer formed by laying molybdenum (Mo) layers and silicon (Si) layers alternately and a light absorbing body formed thereon.
In reflection-type lithography processes, exposure light impinges on a mask from a direction that is inclined from its normal by, for example, about 6° and light reflected from the mask shines on a wafer. To project a high-contrast optical image on the wafer, a light absorbing body is necessary whose thickness (height) is greater than or equal to a prescribed value. However, such a light absorbing body formed on a reflection layer is high in the shadowing effect of interrupting exposure light and causes large dimensional variations in an optical image.